Hollywood keeps making adaptations of Nicholas Sparks novels, even though they've never really burned up the box office. Maybe “The Lucky One” will be, well, the lucky one, but it's hard to imagine why. Sparks films have become their own subclass within the Romance genre; and this one feels so familiar that, in my mind, its details began to blur with those of its predecessors before the closing credits had finished.

Zac Efron plays Logan Thibault, a recently returned Iraq vet, who is determined to track down a beautiful girl (Taylor Schilling), whose photo he found buried in the desert. He doesn't know her name or anything about her, but her image kept him (in his words) “alive,” though, based on some of his actions, not necessarily sane. Now home for good from his third tour of duty, he locates this unwitting guardian angel in a small Louisiana town. Her name is Beth Green, and the photo belonged to her brother, who was killed in action under murky circumstances.

Due to the kind of creaky contrivance on which romantic melodramas are frequently constructed, she mistakes him for a job applicant — she runs a dog training and boarding facility — before he can explain why he's there. Beth's wise old grandma, Nana (Blythe Danner), immediately intuiting that Logan is one of the Good Guys, hires him, despite Beth's misgivings.

At that moment, you think: Wait a minute, Danner is playing her grandmother? Did I hear that right? While a perusal of the two actresses' vital stats reveals that Danner is, in fact, old enough to have begot Schilling's mom, it's still a jolt for those of us of a certain age.

That Nana has better instincts than Beth is soon apparent. Beth is struggling as the single mom of a precocious 8-year-old (Riley Thomas Stewart); her lout of an ex (Jay R. Ferguson) is a local sheriff and son of one of the town's most powerful men (Adam Lefevre). He wants her back and figures that a campaign of harassment and threats will surely recapture her heart.

It's unfortunate that Schilling's previous starring role was Dagne Taggart, the cardboard cartoon of a heroine in 2011's “Atlas Shrugged: Part I.” But, even if that performance hadn't kept popping to mind, it's likely that the casting of Danner and Schilling would still have distractingly made me wonder how the gene pool had deteriorated so significantly in a mere two generations. Beth is frankly a complete pill; and Schilling's uncomfortable, Coulter-ish version of beauty makes her a brittle pill to swallow indeed. So, while Beth is more age-appropriate for Logan, he immediately loses sympathy points for finding her more appealing than Nana in any regard.

With the slightest shift in tone, the story could have been more interestingly shot as a sort of film noir; its basic elements could work either way. But a noirish tone would have required more character ambiguity, which “The Lucky One” studiously avoids. At every turn, Logan comes across as the most admirable being to have walked the earth since roughly 33 A.D. And everybody's problems are tidied up by the end with Swiss Movement precision.

It should also be mentioned that the plot is a diluted modernization of the 1932 Ernst Lubitsch film “The Man I Killed” (aka “Broken Lullaby”), even down to emotionally important scenes of a violin/piano duet. It should go without saying — but I'll say it just for insurance — that neither Sparks nor screenwriter Will Fetters nor director Scott Hicks (“Shine”) can compete.

ANDY KLEIN is the film critic for Marquee. He can also be heard on “FilmWeek” on KPCC-FM (89.3).